I'm finding that my white ceramic gaiwan stains very easily, and there's a ring of dark discoloration at water level after a couple of sessions. It's difficult to remove, too, without hard scrubbing with a rough sponge. I found it odd since the stains on the outside and saucer from drips and spills are very easy to rub off with my thumb. I'm hoping the harsh scrubbing isn't damaging the glaze.

I've recently started using baking soda, mostly just rubbed into a paste with my fingers, to keep glazed, unglazed, and glass teaware bright and clean. This was first suggested to me here on the forum, and it works brilliantly. No more bleach baths, no scrubbing to the point of dulling the finish.

Glazed ceramic ... vinegar FTW! I fill it full strength and let it soak just a bit. I then reuse the vinegar on the next item needing cleaning.

I have noticed that sometimes these adhesions are actually small amounts of tea stained scale which would make removal harder than stains alone. The acid of vinegar seems to work wonders on scale and/or stains.

arcticfox wrote:I tried the baking soda today, and it worked like a charm. Just gentle rubbing with my fingers took off all the stains.

I haven't heard of cultivating a patina on teaware other than zi sha clay. Is this a common thing? Does it actually add anything to the tea?

Accumulated scale on clay kettles can be very beautiful. Hagi turns over time very nice, when tea perforates the clay, and the whole piece changes with the crackles getting more visible. Also Shigaraki turns more beautiful the more you use it. Many Japanese unglazed pots also turn more dark and shiny with use.

On porcelain cups or plates i usually clean them with hot water right after drinking, and wipe them with a tissue or towel. That slows down the build up of tea stains. Once a while, very rarely, i use a mild and un-perfumed detergent and rub the stains off with a sponge, and then use lots of water to wash the detergent off. I don't think that something aggressive like bleach or baking soda is really needed, unless you have an old pot that has decades of accumulated dust and dirt you have to get rid off.Tea ware with more porous glaze such as hagi i never use anything other than hot water on - stains or no stains.